This invention relates to a catheter system that facilitates cardiopulmonary surgeries and enables prolonged circulatory support of the heart.
Heart surgery has generally required major open chest surgical procedures that put the patient at risk. Relatively high mortality rates and complications result from such invasive surgeries. Further, the surgeries require extensive hospitalization and recuperation time.
Surgical methods to correct heart problems are desirable which do not require open chest approaches. Some surgical techniques have been described for particular applications employing an intra-aortic catheter introduced into the vascular system of the patient. An example of such a technique may be found in U.S. Pat. No. 5,458,574. Endovascular techniques described to date, however, typically are not designed for all heart surgical procedures and do not provide access for robotic instruments to both sides of the heart.
Catheters have been described which access the left ventricle, for example, but there are none that are capable of surgically functioning on the right side of the heart. Further, such described catheters do not provide for a means to cross the atrial septum or provide for prolonged right or left ventricular bypass using an external pump, to mechanically support a reversibly failed heart in a closed chest procedure. Such a system which could be placed in both sides of the heart could more effectively resuscitate many cardiac arrest victims than other devices because ventricular decompression would be achievable.
Current methods further do not provide for selective cerebral perfusion, antegrade aortic flow, pulmonary artery flow or peripheral access vessel perfusion and drainage. Such mechanisms are necessary to minimize complications of a vast array related to proper direction of blood flow in the body.
Current methods do not take into account the desirability of perfusing the pulmonary artery or draining the left ventricle for prolonged support of the contracting but failed ventricle, via peripheral access for prolonged isolated right or left or simultaneous biventricular support. A system is needed which enables a broader range of endovascular cardiac surgical procedures, a method for prolonging heart support for certain surgical procedures and a method to mechanically support a reversibly failed heart to achieve direct circulatory arrest, with isolated cerebral perfusion using conventional heart and lung support machines.
The present invention provides a peripheral vascular catheter system versatile enough to access both sides of the heart, provide for prolonged heart support (to mechanically support a reversibly failed heart) to achieve deep hypothermic circulatory arrest with isolated or compartmentalized perfusion enabling surgery on the heart while controlling blood flow, including rate of flow, pressure, temperature, and the perfusion of selected chemicals, to selected parts of the body including but not limited to the brain, spinal cord, lungs, and heart. The invention can also be used to decompress selected chambers of the heart, which may allow some procedures to be performed without the need to stop the heart. The invention can further be used to perfuse a saline solution or the like to selected chambers of the heart to create a clear or bloodless operating field.
The subject biventricular vascular catheter system comprises (a) an elongated catheter shaft configured to be advanceable from a peripheral vessel or artery to and through all chambers of the heart, including across the ventricular or atrial septum, having a proximal end adapted to extend out of the patient and a distal end adapted to move through the patients arteries or vessels and the chambers of the heart, the distal end having multiple fenestrations and a first inner lumen extending therein from a port in the distal end of the shaft to a location in the proximal end; and (b) at least one and preferably a succession of flow control members positioned along the catheter shaft used to isolate or compartmentalize the blood flow to selected parts of the patient""s body.
In one embodiment configured for entry through a femoral artery or vein, to the left or right heart respectively, the first flow control member is located at the proximal end of the catheter shaft proximate the site of entry of the shaft into the patient, the second flow control member is located distal to the first flow control member and is dimensioned and configured so that it sits in the proximal descending thoracic aorta, a third flow control member distal to the second flow control member is dimensioned and configured so that it seats between the coronary ostia and the brachiocephalic artery, and a fourth flow control member distal to the third flow control member is dimensioned and configured so that it seats in the left ventricular outflow tract. Useable flow control members include, but are not limited to, expandable or inflatable members such as an inflatable balloons and valves including collapsible/expandable valves of various configurations including retrograde valves, antegrade valves, and various central flow and peripheral flow valves. A combination of valves and inflatable members may be is used as appropriate for a given procedure, thus In some embodiments, the catheter body can include one or more antegrade and retrograde valves, as well as one or inflatable balloons.
Inflatable balloons and collapsible/deployable valves are well known in the industry and any desirable or practical such inflatable balloon or deployable valve may be used. Inflatable balloons typically include an interior chamber that is in fluid communication with an inflation lumen extending within the catheter shaft from a location from within the respective flow control member to a location in the proximal portion which is adapted to extend out of the patient.
Preferably, the catheter system will also include a second limb branch catheter connected to the catheter shaft at the proximal end, the limb catheter disposed to provide for drainage or perfusion of the peripheral vessel used as an entry for the catheter shaft in order to protect the limb vasculature. Such limb catheters allow drainage or perfusion of the vessel entered to permit continual placement of the catheter for several days, if necessary, for subacute cardiac assist. If neck vessels are accessed, for example, metabolic monitoring access to that limb or to cerebral circulation would be permitted.
In one preferred embodiment, the catheter system preferably includes a self-sealing dual diaphragm chamber instrument entry port branching from the more distal-ending channel of the catheter which has inflow and outflow ports to remove the air from the chamber to prevent an air embolus from occurring and to allow for the safe introduction of large devices.
In another preferred embodiment of the catheter system, the catheter has a catheter guide, preferably with at least one fenestration which enables the guidance of the catheter into and through the chambers of the heart and which may be removed from the catheter while the catheter is located within the heart.
A further preferred embodiment includes multiple circumferential rings which extend axially around the shaft along a portion of the distal end of the shaft, which rings facilitate the movement of the catheter through the heart. The rings are further supported by struts which connect the rings to one another. The struts are arranged so that they are positioned at varying points around the circumference of the catheter tip to prevent kinking.
The catheter system will further preferably accommodate the selective perfusion or drainage of blood either separately or at the same time from within chosen isolated portions of the patients arteries or vessels in which the catheter is deployed.
The system described here encompasses a number of benefits including the following:
(a) the ability to perform intravascular cardiac and pulmonary surgery through the less complicated peripheral access as compared to standard sternotomy or thoracotomy;
(b) the system lessens blood loss, infection risk, pain, hospital stays, expense and delays in return to full activity;
(c) there would be an expected decrease in the possibility of air emboli to the brain when performing surgery inside the heart and with the chest closed compared to current open heart techniques;
(d) better control of myocardial temperature is afforded compared to open chest approaches;
(e) the ability to isolate sub-circulation regions by selectively inflating the compartmentalizing flow control members to isolate sub-circulations such as the coronary, cerebral, pulmonary, neck and limb, and spinal or thoracic sub-circulations;
(f) the ability to perform antegrade aortic perfusion which avoids malperfusion;
(g) the ability to perform pulmonary artery perfusion which bypasses the right ventricle;
(h) the ability to optimally support the acutely failed heart by decompressing ventricles peripherally for acute and subacute mechanical circulatory support which would thus lead to an expected decrease in likelihood of infection, bleeding and pain compared to open chest cannulation for total ventricular support;
(i) the ability to create clear bloodless operating fields within the heart; and
(j) the ability to selectively decompress selected chambers of the heart, which may allow the completion of some procedures without intentional cardiac arrest.
Some of the major goals of the catheter system disclosed here are to provide a catheter and multiple compartment flow control member system, placed by cutdown or percutaneous techniques, for peripheral vessel entry to accomplish intravascular cardiopulmonary biventricular or two-sided access to robotic surgery techniques of intra-cardiopulmonary structures, provided by a system of single and/or double (major) channel catheters; acute (for a period of minutes) deep hypothermic circulatory arrest with the option for selective cerebral perfusion to enable intra-cardiopulmonary surgery; subacute (over a period of days) cardiopulmonary mechanical support, with antegrade aortic and/or pulmonary artery perfusion, biventricular decompression and peripheral vessel protection, to allow recovery of reversible heart failure.
xe2x80x9cAcute circulatory arrestxe2x80x9d refers to the event where the patient""s body is cooled (usually to about 10xc2x0 C.), the assisting blood pump is stopped, and the blood is drained from the body.
xe2x80x9cSubacute mechanical supportxe2x80x9d refers to the event where the circulation is mechanically assisted for multiple days.
xe2x80x9cReversible heart failurexe2x80x9d refers to an acutely injured heart which is expected to recover over time.
xe2x80x9cRetrogradexe2x80x9d and xe2x80x9cantegradexe2x80x9d when used herein in relation to the patient""s vasculature, relate to the direction of normal blood flow and to the direction opposite normal blood flow through a vessel, respectively.
The terms xe2x80x9cproximalxe2x80x9d and xe2x80x9cdistalxe2x80x9d when used herein in relation to instruments used in a cardiac procedure, refer to directions closer and farther away, respectively, from that end of the instrument which is held or manipulated by the operator performing the procedure.
xe2x80x9cFlow Control Valvexe2x80x9d refers to any useable valve including, but not limited to, collapsible valves, which can be selectively expanded or inflated, of various configurations including various central flow and peripheral flow control valves. The valves may be retrograde or antegrade valves as appropriate. Moreover, the valves may be configured to occlude or inhibit fluid flow, hinder fluid flow, direct fluid flow, and occlude or hinder fluid flow in one direction while allowing fluid flow in another. Typically, the flow control valves are external to the catheter and are deployable to control the flow within the circulatory vessle in which they are placed. Antegrade flow control valves allow a greater flow in the antegrade direction than in the retrograde direction. Whereas, retrograde flow control valves allow a greater flow in the retrograde direction than in the antegrade direction.
Terms relating to anatomical parts have the meaning ascribed to them in the art and when they are coupled with an instrument part (e.g. supra-coronary inflation member) they indicate where in the body the instrument part is to be located.
Other terms used herein, unless otherwise defined herein, have the meanings commonly used by those of skill in the art of cardiac surgery.